Gas flow profile modulated control of overlay in plasma CVD films

ABSTRACT

Methods for modulating local stress and overlay error of one or more patterning films may include modulating a gas flow profile of gases introduced into a chamber body, flowing gases within the chamber body toward a substrate, rotating the substrate, and unifying a center-to-edge temperature profile of the substrate by controlling the substrate temperature with a dual zone heater. A chamber for depositing a film may include a chamber body comprising one or more processing regions. The chamber body may include a gas distribution assembly having a blocker plate for delivering gases into the one or more processing regions. The blocker plate may have a first region and a second region, and the first region and second region each may have a plurality of holes. The chamber body may have a dual zone heater.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of U.S. Provisional Patent ApplicationNo. 62/059,751, filed Oct. 3, 2014, which is incorporated by referencein its entirety.

BACKGROUND

1. Field

Embodiments of the present disclosure generally relate to methods andapparatus for depositing film layers on a substrate.

2. Description of the Related Art

A hardmask, such as amorphous hydrogenated carbon, prevents damage anddeformation of delicate materials, such as silicon dioxide or carbondoped silicon oxide. In addition, a hardmask layer may act as an etchmask in conjunction with conventional lithographic techniques to preventthe removal of a material during etching.

A hardmask that is highly transparent to optical radiation, i.e., lightwavelengths between about 400 nm and about 700 nm, is desirable in someapplications, such as lithographic processing. Transparency to aparticular wavelength of light allows for more accurate lithographicregistration, which in turn allows for precise alignment of a mask withspecific locations on substrate. The transparency of a material to agiven frequency of light is generally quantified as the extinctioncoefficient of a material, also referred to as the absorptioncoefficient (κ). For example, for an amorphous hydrogenated carbon layerthat is approximately 6000 Å to 7000 Å thick, the amorphous hydrogenatedcarbon layer should have an absorption coefficient of 0.12 or less atthe frequency of light used for the lithographic registration, forexample 630 nm, otherwise the mask may not be aligned accurately. Alayer with absorption coefficient greater than 0.12 may also be used,but layer thickness may have to be reduced to achieve accuratelithographic registration. Regarding overlay error, high κ values do notresult in overlay error, but high κ range may result in overlay error.

Amorphous hydrogenated carbon, also referred to as amorphous carbon anddenoted α-C:H, is essentially a carbon material with no long-rangecrystalline order which may contain a substantial hydrogen content, forexample on the order of about 10 to 45 atomic %. The α-C:H is used as ahardmask material in semiconductor applications because of its chemicalinertness, optical transparency, and good mechanical properties. Whileα-C:H films can be deposited via various techniques, plasma enhancedchemical vapor deposition (PECVD) may be used due to cost efficiency andfilm property tunability. In a typical PECVD process, plasma isinitiated in a chamber to create, for example, excited CH— radicals. Theexcited CH— radicals are chemically bound to the surface of a substratepositioned in the chamber, forming the α-C:H film thereon.

Between one layer and the next layer that overlays the previous one, theindividual patterns of the one layer and the next layer should bealigned. A measurement of alignment marks may be obtained by a metrologytool which is then used by a lithography tool to align the subsequentlayers during exposure and again after a lithography process to rechecka performance of the alignment. However, overlay errors between layersare inevitable, and error budgets are calculated by integrated circuitdesigners for which manufacturing must meet. Overlay error budget isdefined as errors induced by lithographic scannerinaccuracy/misalignment, non-linear process with-in film variations,mask-to-mask variations, and metrology errors. Overlay errors of thedevice structure may originate from different error sources, such asoverlay errors from previous exposure tool, current exposure tool, amatching error between the overlay errors of the previous exposuretool/metrology tool and of the current exposure tool/metrology tool, orsubstrate film layer deformation caused by film stress.

As device dimensions continue to shrink, next-generation lithography(NGL) processes should have overlay error budget of <6-8 nm within asubstrate. During, for example, PECVD processes, local partialpressures, temperature, residence time and/or reactivity of gaseouscomponents may give a non-uniform morphology of the deposited film,wherein, for example, local stress of the film differs in variousregions of the film. Such non-uniform morphology results in overlayerrors locally at various regions on the film. Furthermore, nextgeneration CVD hardmask films contribute >50% of overlay error,significantly reducing device yield and performance. There is a need inthe art to reduce overlay error within deposited multilayers and a needfor a method of depositing a material layer useful for integratedcircuit fabrication which can be conformally deposited on substrateshaving topographic features.

SUMMARY

In one embodiment, a method of modulating local stress and overlay errorof one or more patterning films comprises modulating a gas flow profileof gases via a blocker plate comprising a first region and a secondregion, wherein the first region and second region each have a pluralityof holes. The method may include introducing the gases into a chamberbody through the pluralities of holes of the first and second regions ofthe blocker plate. The method may include flowing gases within thechamber body toward a first region and a second region of a substrate.The method may include rotating the substrate after deposition of atleast a partial film onto the substrate.

In another embodiment, a method of modulating local stress and overlayerror of one or more patterning films comprises modulating a gas flowprofile of gases via a blocker plate comprising a first region and asecond region, wherein the first region and second region each have aplurality of holes. The method may include introducing the gases into achamber body through the pluralities of holes of the first and secondregions of the blocker plate. The method may include flowing gaseswithin the chamber body toward a first region and a second region of asubstrate. The method may include unifying a center-to-edge temperatureprofile of the substrate by controlling the substrate temperature with adual zone heater, wherein the dual zone heater comprises a first heatingzone and a second heating zone, wherein the second heating zonecircumscribes the first heating zone.

In another embodiment, a chamber for depositing a film comprises achamber body comprising one or more processing regions. The chamber bodymay comprise a gas distribution assembly comprising a blocker plate fordelivering gases into the one or more processing regions, wherein theblocker plate comprises a first region and a second region, wherein thefirst region and second region each comprises a plurality of holes. Thechamber body may comprise a dual zone heater, wherein the dual zoneheater comprises a first heating zone and a second heating zone, whereinthe second heating zone circumscribes the first heating zone, andwherein one of the heating zones is about 5 mm to about 200 mm from acenter axis of the dual zone heater. The chamber body may comprise ashadow ring configured to support a substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentdisclosure can be understood in detail, a more particular description ofthe disclosure, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlyexemplary embodiments and are therefore not to be considered limiting ofits scope and may admit to other equally effective embodiments.

FIGS. 1A-1B each illustrate a schematic cross-sectional view of asubstrate at different stages of an integrated circuit fabricationsequence incorporating an amorphous carbon layer as a hardmask.

FIG. 2A illustrates gas flow morphology with respect to κ-range andlocal stress.

FIGS. 2B-2C illustrate radial gas flow with respect to κ-range and localstress.

FIG. 2D illustrates radial and azimuthal components of κ-633 nm andlocal stress.

FIG. 2E illustrates the effect of “more flow-at-center” in combinationwith substrate rotation on local stress and overlay error.

FIG. 2F illustrates the temperature profiles of a single zone heater anddual zone heater.

FIG. 3 is a schematic cross-sectional diagram of an exemplary processingchamber that may be used for practicing some embodiments of the presentdisclosure.

FIG. 4 is a process flow diagram illustrating a method according to someembodiments of the present disclosure.

FIGS. 5A-5C illustrates bottom views of a blocker plate according tosome embodiments of the present disclosure.

FIG. 6 is a bottom view of a showerhead according to some embodiments ofthe present disclosure.

FIG. 7 is a plan view of a shadow ring according to some embodiments ofthe present disclosure.

FIG. 8 is a perspective view of a dual zone heater according to someembodiments of the present disclosure.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements and features of oneembodiment may be beneficially incorporated in other embodiments withoutfurther recitation.

DETAILED DESCRIPTION

FIGS. 1A-1B illustrate schematic cross-sectional views of a substrate100 at different stages of an integrated circuit fabrication sequenceincorporating an amorphous carbon-hydrogen (α-C:H) layer as a hardmask.A substrate structure 150 denotes the substrate 100 together with othermaterial layers formed on the substrate 100. FIG. 1A illustrates across-sectional view of a substrate structure 150 having a materiallayer 102 that has been conventionally formed thereon. The materiallayer 102 may be a low-k material such as an oxide having pores, e.g.,SiO₂, Si3N4, oxides, nitrides, or a carbon-doped silicon oxide.

FIG. 1B illustrates an amorphous carbon layer 104 deposited on thesubstrate structure 150 of FIG. 1A. The amorphous carbon layer 104 isformed on the substrate structure 150 by conventional means, such asPECVD. The thickness of amorphous carbon layer 104 is variable dependingon the specific stage of processing. Typically, amorphous carbon layer104 has a thickness in the range of about 500 Å to about 10,000 Å.

Aspects of the present disclosure contemplate the use of a relativelylarge flow rate of argon or other heavy noble gas, such as krypton orxenon, as a diluent gas during α-C:H film deposition to increase theresultant film density (and therefore etch selectivity), the depositionrate of the film, and the conformality of the film to features on thesurface of the substrate. The application of a heavy noble gas as alarge flow rate diluent gas also improves the efficiency of hydrocarbonprecursor utilization during the deposition process, minimizing unwanteddeposition on interior surfaces of the deposition chamber. Helium hasbeen used as the primary non-reactive component of the working gas in aPECVD chamber for α-C:H film deposition since it is easily ionized andis therefore advantageous for initiating plasma in a chamber with a lowrisk of arcing.

FIG. 3 presents a cross-sectional, schematic diagram of a chemical vapordeposition (CVD) chamber 300 for depositing an advanced patterning filmsuch as an amorphous carbon layer. One example of the chamber 300 maybe, for example, a PRODUCER® chamber or XP PRECISION™ chambermanufactured by Applied Materials, Inc., Santa Clara, Calif. ThePRODUCER® CVD chamber (200 mm or 300 mm) has two isolated processingregions that may be used to deposit carbon-doped silicon oxides andother materials.

The deposition chamber 300 has a chamber body 302 that defines separateprocessing regions 318, 320. Each processing region 318, 320 has apedestal 328 for supporting a substrate (not shown) within the chamber300. The pedestal 328 typically includes a heating element (not shown).The pedestal 328 may be movably disposed in each processing region 318,320 by a stem 326 which extends through the bottom of the chamber body302 where it is connected to a drive system 303. Internally movable liftpins (not shown) may be provided in the pedestal 328 to engage a lowersurface of the substrate. The lift pins may be engaged by a liftmechanism (not shown) to receive a substrate before processing, or tolift the substrate after deposition for transfer to the next station.

Each of the processing regions 318, 320 may also include a gasdistribution assembly 308 disposed through a chamber lid 304 to delivergases into the processing regions 318, 320. The gas distributionassembly 308 of each processing region normally includes a gas inletpassage 340 through manifold 348 which delivers gas from a gasdistribution manifold 319 through a blocker plate 346 and then through ashowerhead 342. The showerhead 342 includes a plurality of holes (notshown) through which gaseous mixtures are injected during processing. AnRF (radio frequency) supply 325 provides a bias potential to theshowerhead 342 to facilitate generation of a plasma between theshowerhead and the pedestal 328. During a plasma-enhanced chemical vapordeposition process, the pedestal 328 may serve as a cathode forgenerating the RF bias within the chamber body 302. The cathode iselectrically coupled to an electrode power supply to generate acapacitive electric field in the deposition chamber 300. Typically an RFvoltage is applied to the cathode while the chamber body 302 iselectrically grounded. Power applied to the pedestal 328 creates asubstrate bias in the form of a negative voltage on the upper surface ofthe substrate. This negative voltage is used to attract ions from theplasma formed in the chamber 300 to the upper surface of the substrate.The capacitive electric field forms a bias which accelerates inductivelyformed plasma species toward the substrate to provide a more verticallyoriented anisotropic filming of the substrate during deposition, andetching of the substrate during cleaning.

During processing, process gases may be uniformly distributed radiallyacross the substrate surface. The plasma is formed from one or moreprocess gases or a gas mixture by applying RF energy from the RF powersupply 325 to the showerhead 342, which acts as a powered electrode.Film deposition takes place when the substrate is exposed to the plasmaand the reactive gases provided therein. The chamber walls 312 aretypically grounded. The RF power supply 325 can supply either a singleor mixed-frequency RF signal to the showerhead 342 to enhance thedecomposition of any gases introduced into the processing regions 318,320.

In some embodiments, process gases are distributed radially “moreflow-at-center” or “more flow-at-edge” across the substrate surfacedepending on, for example, the configuration of blocker plate 346, asdescribed in more detail below.

A system controller 334 controls the functions of various componentssuch as the RF power supply 325, the drive system 303, the liftmechanism, the gas distribution manifold 319, and other associatedchamber and/or processing functions. The system controller 334 executessystem control software stored in a memory 338, which may be a hard diskdrive, and can include analog and digital input/output boards, interfaceboards, and stepper motor controller boards. Optical and/or magneticsensors are generally used to move and determine the position of movablemechanical assemblies.

The above CVD system description is mainly for illustrative purposes,and other plasma processing chambers may also be employed for practicingembodiments of the present disclosure.

A wide variety of process gas mixtures may be used in the depositionprocess. The process gas may be introduced into the processing chamberat a flow rate in a range of between about 10 mg/min. and about 5,000mg/min., such as between about 300 mg/min. and about 3,000 mg/min.

The gas mixture optionally includes one or more carrier gases. Examplesof carrier gases that may be used include helium, argon, carbon dioxide,and combinations thereof. The one or more carrier gases may beintroduced into the processing chamber at a flow rate less than about20,000 standard cubic centimeter per minute (sccm), depending in partupon the size of the interior of the chamber. The flow of carrier gasmay be in a range of about 500 sccm to about 1,500 sccm, about 1,000sccm. In some processes, an inert gas such as helium or argon is putinto the processing chamber to stabilize the pressure in the chamberbefore reactive process gases are introduced.

The gas mixture may include one or more oxidizing gases. Suitableoxidizing gases include oxygen (O₂), ozone (O₃), nitrous oxide (N₂O),carbon monoxide (CO), carbon dioxide (CO₂), and combinations thereof.The flow of oxidizing gas may be in a range of about 100 sccm to about3,000 sccm, depending in part upon the size of the interior of thechamber. Typically, the flow of oxidizing gas is in a range of about 100sccm to about 1,000 sccm. Disassociation of oxygen or the oxygencontaining compounds may occur in a microwave chamber prior to enteringthe deposition chamber and/or by RF power as applied to process gaswithin the chamber.

During deposition, a controlled plasma is typically formed in thechamber adjacent to the substrate by RF energy applied to the showerheadusing an RF power supply 325 as depicted in FIG. 3. Alternatively, RFpower may be provided to the substrate support. The plasma may begenerated using high frequency RF (HFRF) power, as well as low frequencyRF (LFRF) power (e.g., dual frequency RF), constant RF, pulsed RF, orany other plasma generation technique. The RF power supply 325 cansupply a single frequency RF between about 5 MHz and about 300 MHz. Inaddition, the RF power supply 325 may also supply a single frequencyLFRF between about 300 Hz to about 1,000 kHz to supply a mixed frequencyto enhance the decomposition of reactive species of the process gasintroduced into the process chamber. The RF power may be cycled orpulsed to reduce heating of the substrate and promote greater porosityin the deposited film. Suitable RF power may be a power in a range ofabout 10 W to about 5,000 W, about 200 W to about 1000 W. Suitable LFRFpower may be a power in a range of about 0 W to about 5,000 W, about 0 Wto about 200 W.

Deposition Process:

Aspects of the present disclosure contemplate the deposition of an α-C:Hlayer by a process that includes introducing a hydrocarbon source, aplasma-initiating gas, and a diluent gas into a processing chamber. Thehydrocarbon source is a mixture of one or more hydrocarbon compounds.The hydrocarbon source may include a gas-phase hydrocarbon compound,such as C₃H₆, and/or a gas mixture including vapors of a liquid-phasehydrocarbon compound and a carrier gas. The plasma-initiating gas may behelium, because it is readily ionized, however other gases, such asargon, may also be used. The diluent gas is an easily ionized,relatively massive, and chemically inert gas. Exemplary diluent gasesinclude argon, krypton, and xenon.

Additionally, amorphous carbon layers formed using partially orcompletely doped derivatives of hydrocarbon compounds may also benefitfrom method of the present disclosure. Derivatives includenitrogen-containing, fluorine-containing, oxygen-containing, hydroxylgroup-containing, and boron-containing derivatives of hydrocarboncompounds. The hydrocarbon compounds may be functionalized withnitrogen-containing substituents and/or be deposited with anitrogen-containing gas, such as ammonia. The hydrocarbon compounds maybe functionalized with fluorine-containing and/or oxygen-containingsubstituents.

The α-C:H deposition process with argon dilution may be a PECVD process.The α-C:H layer may be deposited from the processing gas by maintaininga substrate temperature between about 100° C. and about 650° C. in orderto minimize the absorption coefficient range of the resultant film. Theprocess further includes maintaining a chamber pressure between about0.4 Torr and about 10 Torr. The deposition rate may be between about2,000 Å/min. and about 20,000 Å/min. The hydrocarbon source, aplasma-initiating gas, and a diluent gas may be introduced into thechamber and plasma is initiated to begin deposition. Theplasma-initiating gas may be helium or another easily ionized gas and isintroduced into the chamber before the hydrocarbon source and thediluent gas, which allows a stable plasma to be formed and reduces thechances of arcing. Plasma is generated by applying RF power at a powerdensity to substrate surface area of between about 0.7 W/cm² and about 3W/cm², such as between about 1.1 to 2.3 W/cm². Electrode spacing, e.g.,the distance between the substrate and the showerhead, may be betweenabout 200 mils and about 1000 mils.

A dual-frequency RF system may be used to generate plasma. The dualfrequency is believed to provide independent control of flux and ionenergy, since the energy of the ions hitting the film surface influencesthe film density. Without being bound by theory, the high frequencyplasma controls plasma density and the low frequency plasma controlskinetic energy of the ions hitting the substrate surface. Adual-frequency source of mixed RF power provides a high frequency powerin a range between about 10 MHz and about 30 MHz, for example, about13.56 MHz, as well as a low frequency power in a range of between about10 KHz and about 1 MHz, for example, about 350 KHz. When a dualfrequency RF system is used to deposit an α-C:H film, the ratio of thesecond RF power to the total mixed frequency power may be less thanabout 0.6 to 1.0 (0.6:1). The applied RF power and use of one or morefrequencies may be varied based upon the substrate size and theequipment used.

Very high film stress in a deposited α-C:H film causes problems such aspoor adhesion of the α-C:H film to substrate surfaces and/or cracking ofthe α-C:H film. Therefore, the addition of argon or other diluent beyonda certain molar ratio relative to the hydrocarbon compound willdeleteriously affect the properties of the film. Hence, there is aprocess window, wherein the ratio of molar flow rate of argon diluent tothe molar flow rate of hydrocarbon compound into the PECVD chamber maybe maintained between about 2:1 and about 40:1, depending on the desiredproperties of the deposited film. For the deposition of some α-C:Hfilms, the range of the ratio of molar flow rate of argon diluent to themolar flow rate of hydrocarbon compound into the PECVD chamber may bebetween about 10:1 and about 14:1.

Ordinarily, higher substrate temperature during deposition is a processparameter used to encourage the formation of a higher density film.Because the argon-diluted process already increases density for thereasons described above, substrate temperature may be reduced duringdeposition, for example to as low as about 300° C., and still produce afilm of a desired density, e.g., from about 1.2 g/cc to about 2.2 g/cc.Hence, the argon-dilution process may produce a relatively high densityfilm with an absorption coefficient as low as about 0.09. Further, lowerprocessing temperatures are generally desirable for all substrates sincethis lowers the thermal budget of the process, protecting devices formedthereon from dopant migration.

Process-induced overlay error relates to local curvature and bow of adeposited film, which can be measured as local stress variations withina film. Film stress increases overlay error because a variation ofsp²/sp³ binding affects the structural uniformity across the film, e.g.a hardmask. For example, when temperature distribution across a surfaceis profiled using a thermocouple, the center of the substrate may have ahigher temperature than the edge of the substrate, resulting in thehigher temperature region of the substrate comprising more sp² characterthan lower temperature regions of the substrate. Furthermore, absorptioncoefficient (κ) strongly depends on film morphology and molecularstructure (i.e., a film region with more sp² character absorbs lightmore efficiently than a film region with less sp² character). As such,the absorption coefficient may be monitored, e.g. at 633 nm, todetermine film morphology across a substrate, as shown in FIG. 2A, usingvarious metrology tools. Metrology tools refer to an interferometricbased tool which may be utilized to determine a local stress map, forexample, from KLA Tencor's Aleris series. However, it is contemplatedthat other tools from other manufacturers suitably adapted to performstress measurement processes may also be utilized.

By monitoring film morphology across a substrate, deposition parametersof a deposition process and/or hardware of a deposition chamber may bevaried to deposit one or more films, wherein each of the one or morefilms comprises a uniform morphology and reduced overlay error.

FIG. 4 is a process flow diagram illustrating a first method accordingto some embodiments of the present disclosure. As shown in FIG. 4, localstress and overlay error of one or more patterning films may bemodulated by modulating a gas flow profile of gases introduced into achamber body (block 402). The gases may then be flowed within thechamber body toward a substrate (block 404). A gas flow profile may bemodulated, for example, by altering the density of holes of blockerplate 346. Density of holes refers to the spacing between each of theholes in a particular region of blocker plate 346. FIG. 5A is a bottomview of the blocker plate 346. As shown in FIG. 5A, the inner region 522is circular in shape and has a greater density of holes 520 relative tothe density of holes 520 of the outer region 524. A diameter 502 of theinner region 522 corresponds to the inner diameter of a correspondingshowerhead 342. The outer region 524 is annular, or ring-like, in shapeand surrounds the inner region 522. An outer diameter 504 of the outerregion 524 corresponds to partially or substantially the outer diameterof showerhead 342.

The holes 520 in the inner region 522 are more closely spaced from oneanother relative to the spacing of the holes 520 in the outer region524. Thus, the density of holes 520 in the outer region 524 is less thanthe density of holes 520 in the inner region 522. Thus, gas flow throughthe blocker plate 346 will be greater at inner region 522 than gas flowthrough outer region 524 because of the larger density of holes 520 ofthe inner region 522 than density of holes 520 of the outer region 524.In other words, there may be more gas flow toward the center ofshowerhead 342 than toward the edge of showerhead 342.

FIG. 5B is a bottom view of an alternate embodiment of blocker plate346. As shown in FIG. 5B, the holes 520 in the outer region 524 are moreclosely spaced from one another relative to the spacing of the holes 520in the inner region 522. Thus, the density of holes 520 of outer region524 may be greater than the density of holes 520 of the inner region522. Thus, gas flow through the blocker plate 346 will be greater atouter region 524 than gas flow at inner region 522 because of the largerdensity of holes 520 in the outer region 524 than density of holes 520of the inner region 522. In other words, there may be more gas flow atthe edge of showerhead 342 than at the center of showerhead 342.

FIG. 5C is a bottom view of an alternate embodiment of blocker plate346. As shown in FIG. 5C, the holes 520 in the outer region 524 arespaced from one another substantially similar to the spacing of theholes 520 in the inner region 522. Thus, the density of holes 520 ofouter region 524 is substantially similar to the density of holes 520 ofthe inner region 522. Thus, gas flow through the blocker plate 346 atouter region 524 and inner region 522 will be substantially uniformbecause the density of holes 520 in the outer region 524 and the innerregion 522 is substantially uniform. In other words, there may be asubstantially uniform gas flow across the entire substrate.

In some embodiments, the surface area of inner region 522 may besubstantially similar to the surface area of outer region 524 or,alternatively, may be different than the surface area of outer region524, depending on the amount of desired gas flow toward the centerand/or edge of a substrate. Furthermore, blocker plate 346 may compriseadditional regions (not shown) of varying density of holes 520.

Alternatively, or in addition to blocker plate 346, the showerhead 342may be configured to adjust a gas flow profile. FIG. 6 is a bottom viewof the showerhead 342. As shown in FIG. 6, the inner region 622 iscircular in shape and has a greater density of holes 620 relative to thedensity of holes 620 of the outer region 624. A diameter 602 of theinner region 622 corresponds to the inner diameter of a correspondingsubstrate. The outer region 624 is annular, or ring-like, in shape andsurrounds the inner region 622. An outer diameter 604 of the outerregion 624 corresponds to substantially the outer diameter of asubstrate.

The showerhead 342 is disposed within the processing volume 318, 320 andcoupled to the chamber body 302. A ledge 626, or other similarstructure, of the showerhead 326 is configured to mate with a supportwithin the chamber body 302, such as blocker plate 346. The blockerplate 346 spaces the showerhead 342 from the chamber body 302 andpositions the showerhead 342 within the processing volume 318. Theshowerhead 342 and blocker plate 346 may be fastened together by a boltor screw, or other similar fastening apparatus.

The holes 620 in the inner region 622 are more closely spaced from oneanother relative to the spacing of the holes 620 in the outer region624. Thus, the density of holes 620 in the outer region 624 is less thanthe density of holes 620 in the inner region 622. In such embodiments,gas flow through the showerhead 342 will be greater at inner region 622than gas flow through outer region 624 because of the larger density ofholes 620 of the inner region 622 than density of holes 620 of the outerregion 624. In other words, there may be more gas flow toward the centerof the substrate than toward the edge of the substrate.

Alternatively, the holes 620 in the outer region 624 may be more closelyspaced from one another relative to the spacing of the holes 620 in theinner region 622. Thus, the density of holes 620 of outer region 624 maybe greater than the density of holes 620 of the inner region 622. Thus,gas flow through the showerhead 342 will be greater at outer region 624than gas flow at inner region 622 because of the larger density of holes620 in the outer region 624 than density of holes 620 of the innerregion 622. In other words, there may be more gas flow at the edge ofthe substrate than at the center of the substrate.

Alternatively, the holes 620 in the outer region 624 may be spaced fromone another substantially similar to the spacing of the holes 620 in theinner region 622. Thus, the density of holes 620 of outer region 624 issubstantially similar to the density of holes 620 of the inner region622. Thus, gas flow through the showerhead 342 at outer region 624 andinner region 622 will be substantially uniform because the density ofholes 620 in the outer region 624 and the inner region 622 issubstantially uniform. In other words, there may be a substantiallyuniform gas flow across the entire substrate.

In some embodiments, the surface area of inner region 622 may besubstantially similar to the surface area of outer region 624 or,alternatively, may be different from the surface area of outer region624 depending on the amount of desired gas flow toward the center and/oredge of a substrate. Furthermore, showerhead 342 may comprise additionalregions (not shown) of varying density of holes 620.

FIGS. 2B-2C illustrate radial gas flow with respect to κ-range and localstress. As shown in FIGS. 2B-2C, for uniform flow across a substrate,lower κ-range reduces process-induced local stress variation and overlayerror. However, this trend is reversed with “more flow-at-center”deposition where a lower κ-range does not improve overlay due toincrease in substrate-scale stress. Nonetheless, “more flow-at-center”allows significant reduction (>50%) in overall κ-range and stresscompared to “uniform flow” and “more flow-at-edge” conditions. Thus, gasprofile modulation provides an optimum point of κ-range where control inoverlay error and local stress variation can be achieved.

In some embodiments, κ-range and local stress may be improved bysubstrate rotation, corresponding to block 406 of FIG. 4. FIG. 7 is aplan view of a shadow ring 702 for supporting a substrate according tosome embodiments of the present disclosure. As shown in FIG. 7, theshadow ring 702 may comprise one or more notches 710 which may be usedto facilitate angles of rotation of the substrate. Optionally, anex-situ rotation may be performed. An ex-situ rotation may be performedwherein the substrate may be removed from chamber body 302, rotated andreentered into chamber body 302 for further processing. For example, arobot blade (not shown) may enter the chamber through a slit valvedisposed through a wall of the chamber, wherein the robot arm thenengages a bottom surface of the substrate that is being supported bylift pins. The robot blade may remove the substrate from the chamber.The substrate may be rotated in a clockwise or counterclockwisedirection between about 15 degrees to about 345 degrees, about 150degrees to about 250 degrees, about 180 degrees. In some embodiments,the substrate comprises one or more notches (not shown) to facilitatesubstrate rotation. After rotation, the substrate may be reentered intothe chamber for further processing.

An ex-situ rotation may be performed in-between deposition of filmlayers. Alternatively, ex-situ rotation may be performed by interruptingthe deposition of a film layer, followed by removal of the substratefrom chamber body 302, even without the risk of native layer formation.The substrate may then be rotated and reentered into chamber body 302.Deposition of the film layer may then resume within chamber body 302.

FIG. 2D illustrates radial (i.e., controlled by flow profile andtemperature offsets) and azimuthal (i.e., controlled by substraterotation) components of κ-633 nm and local stress (denoted σ_(xx)). Asshown in FIG. 2D, substrate rotation reduces local stress and κ-rangewithin a deposited film. Substrate rotation may also improve thicknessuniformity of a deposited film by normalizing thickness variationintroduced by, for example, hardware features. FIG. 2E illustrates theeffect of “more flow-at-center” in combination with substrate rotationon local stress and overlay error. As shown in FIG. 2E, a 50% reductionin stress (σ_(xx)) may be obtained with “more flow-at-center” comparedto uniform flow. 180° ex-situ rotation at half film thickness furtherreduces stress (σ_(xx)) by greater than 75%, and an overlay error ofabout 6 nm to about 8 nm may be obtained.

In some embodiments, κ-range and local stress may be improved byunifying a center-to-edge temperature profile of the substrate bycontrolling the substrate temperature with a dual zone heater,corresponding to block 408 of FIG. 4. As described above, during atypical PECVD process of, for example, an α-C:H film, the center of thesubstrate may have a higher temperature than the edge of the substrate.In other words, temperature may decrease radially from the center of asubstrate during a deposition process. Thermal uniformity (and κ-rangeminimization) of a substrate may be obtained using a dual zone heater.FIG. 8 is a perspective view of a dual zone heater 802 according to someembodiments of the present disclosure. As shown in FIG. 8, dual zoneheater 802 has a plate 810 and stem 812. Plate 810 may comprise ceramicmaterial. In some embodiments, plate 810 corresponds to pedestal 328within chamber body 302 and stem 812 corresponds to stem 326 withinchamber body 302. Plate 810 may comprise lift pins (not shown) to engagea lower surface of a substrate. The space between the Plate 810 and thesubstrate created by the lift pins allows, for example, a robot blade toengage a bottom surface of a substrate during an ex-situ substraterotation process. Plate 810 is coupled with stem 812, wherein plate 810is movably disposed within a processing volume 318 of the chamber body302. Plate 810 may comprise two or more heating zones which may beconfigured to provide one or more temperatures across the surface ofplate 810 and surface of a substrate. For example, face plate 810 maycomprise a first heating zone and second heating zone, the secondheating zone circumscribes the first heating zone. In other words, thesecond heating zone is disposed radially beyond the first heating zone.During a deposition process, the first heating zone may have atemperature different from the temperature of the second heating zone.The temperature of the first heating zone may be less than, equal to, orgreater than the temperature of the second heating zone. Face plate 810may comprise additional heating zones. Face plate 810 may comprisebetween about two to twenty heating zones, about two to ten heatingzones, about two to four heating zones. In some embodiments, one of theheating zones is about 5 mm to about 200 mm from a center axis of thedual zone heater, about 90 to about 140 nm from a center axis of thedual zone heater, about 110 mm to about 120 mm from a center axis of thedual zone heater. The temperature of the two or more heating zones maybe controlled by one or more heating coils (not shown) disposed in anarrangement along within plate 810. The heating coils may be configuredto heat a first heating zone to a first temperature and a second heatingzone to a second temperature. Alternatively, temperature of the two ormore heating zones may be controlled by one or more fluid channels (notshown) configured to house a heating or cooling fluid. FIG. 2Fillustrates the respective temperature profiles of a single zone heaterand dual zone heater. As shown in FIG. 2F, a dual zone heater improvestemperature uniformity by unifying a center-to-edge temperature profile,which reduces local stress and overlay non-uniformity by >50%.

Methods for modulating local stress and overlay error of one or morepatterning films may include modulating a gas flow profile of gasesintroduced into a chamber body, flowing gases within the chamber bodytoward a substrate, rotating the substrate, and unifying acenter-to-edge temperature profile of the substrate by controlling thesubstrate temperature with a dual zone heater. A chamber for depositinga film may include a chamber body comprising one or more processingregions. The chamber body may include a gas distribution assembly havinga blocker plate for delivering gases into the one or more processingregions. The blocker plate may have a first region and a second region,and the first region and second region each may have a plurality ofholes. The chamber body may have a dual zone heater. Methods andapparatus of the present disclosure may reduce overlay error withindeposited multilayers and allow deposition of a material layer usefulfor integrated circuit fabrication which can be conformally deposited onsubstrates having topographic features. Methods and apparatus of thepresent disclosure may reduce overall processing time by eliminatinglithographic and scanner based metrology steps, which, for example,reduces the amount of time needed to determine an optimal filmcomposition.

While the foregoing is directed to embodiments of the presentdisclosure, other and further embodiments of the present disclosure maybe devised without departing from the basic scope thereof, and the scopethereof is determined by the claims that follow.

What is claimed is:
 1. A method of modulating local stress and overlayerror of one or more patterning films, comprising: modulating a gas flowprofile of gases via a blocker plate comprising a first region and asecond region, wherein the first region and second region each have aplurality of holes, wherein the plurality of holes of the first regionare spaced more closely relative to one another than the plurality ofholes of the second region; introducing the gases into a chamber bodythrough the holes of the first region of the blocker plate and thesecond region of the blocker plate; flowing the gases within the chamberbody toward a first region and a second region of a substrate; androtating the substrate after deposition of at least a partial film ontothe substrate.
 2. The method of claim 1, further comprising: unifying acenter-to-edge temperature profile of the substrate by controlling thesubstrate temperature with a dual zone heater, wherein the dual zoneheater comprises a first heating zone and a second heating zone, whereinthe second heating zone circumscribes the first heating zone, andwherein a temperature of the first heating zone is different than atemperature of the second heating zone.
 3. The method of claim 1,further comprising: monitoring film morphology across one or more of thepatterning films with a metrology tool.
 4. The method of claim 1,wherein rotating the substrate is performed ex-situ.
 5. The method ofclaim 1, wherein the first region of the blocker plate is a centerregion and the second region of the blocker plate is an edge region. 6.The method of claim 1, wherein the substrate is rotated while supportedby a shadow ring.
 7. The method of claim 1, wherein the substrate isrotated 180° .
 8. The method of claim 1, wherein a pressure within thechamber body is about 0.4T to about 10 T.
 9. The method of claim 1,further comprising applying an RF voltage to a showerhead.
 10. Themethod of claim 1, wherein the gases comprise one or more carrier gasesselected from the group consisting of helium, argon, carbon dioxide, andcombinations thereof.
 11. The method of claim 10, wherein a flow rate ofthe carrier gas is between about 500 sccm to about 1,500 sccm.
 12. Themethod of claim 1, wherein the gases comprise an oxidizing gas selectedfrom the group consisting of O₂, O₃, N₂O, CO, and carbon dioxide. 13.The method of claim 12, wherein a flow rate of the oxidizing gas isbetween about 100 sccm to about 3,000 sccm.
 14. The method of claim 1,wherein the gases comprise a hydrocarbon compound.
 15. The method ofclaim 14, wherein a ratio of molar flow of diluent gas to molar flowrate of hydrocarbon gas is between about 2:1 and about 40:1.
 16. Themethod of claim 14, wherein the hydrocarbon compound is anitrogen-containing hydrocarbon, a fluorine-containing hydrocarbon, anoxygen-containing hydrocarbon, a hydroxyl-containing hydrocarbon, or aboron-containing hydrocarbon.
 17. The method of claim 1, wherein thegases comprise krypton, xenon, or argon.
 18. The method of claim 2,wherein the temperature of the first heating zone and the temperature ofthe second heating zone are maintained between about 100° C. and about650° C.
 19. The method of claim 1, wherein the modulating a gas flowprofile of gases is further carried out via a showerhead comprising afirst region and a second region, wherein the first region and secondregion each have a plurality of holes, wherein the first regioncomprises a higher density of the plurality of holes than a density ofthe plurality of holes of the second region.
 20. The method of claim 1,further comprising: unifying a center-to-edge temperature profile of thesubstrate by controlling the substrate temperature with a dual zoneheater, wherein the dual zone heater comprises a first heating zone anda second heating zone, and wherein the second heating zone circumscribesthe first heating zone.